The present invention relates to telescoping slide assemblies having interconnected slide members, and particularly to bearing mechanisms for enhancing movement of a slide member in a telescoping slide assembly. More particularly, the invention relates to a ball bearing retainer assembly for use in a telescoping slide assembly.
Telescoping slide assemblies are well known. Telescoping slide assemblies have been mounted to drawers and cabinets to permit easy movement of a drawer between a retracted position inside a cabinet and an extended position outside the cabinet. See, for example, U.S. Pat. No. 3,712,690 to Maxwell S. Fall. Slide assemblies can also be used to move equipment-carrying platforms and a wide variety of other items between retracted and extended positions. In some cases, the slide assemblies are mounted on the side of the unit to be moved while in other cases the slide assemblies are included on the bottom of the unit to be moved.
Some telescoping slide assemblies have three interconnected slide members including a stationary slide member, a load-carrying (or chassis) slide member, and an intermediate slide member therebetween. Other telescoping slide assemblies have two interconnected slide members including an outer slide member and an inner slide member that is movable relative to the outer slide member along a path back and forth inside the outer slide member. Of course, a telescoping slide assembly may include more than three slide members.
Ball bearing slide assemblies using ball bearing retainers are well known. See, for example, U.S. Pat. Nos. 2,606,909; 3,205,025; 3,389,949; 3,488,097; 3,679,275; 3,687,505; 3,738,716; 3,801,166; and 4,089,568. These ball bearing retainers move relative to the slide members in each slide assembly.
One problem facing a maker of telescoping slide assemblies is how to develop a way to maintain a smooth running telescoping slide assembly even though the slide assembly is subjected to moderate or severe shock and vibration when it is in its fully retracted closed position. Such a condition could exist, for example, when telescoping slide assemblies are used to support a platform for movement into and out of a vibrating machine as disclosed herein and in the James D. Hobbs et al U.S. patent application Ser. No. 08/207,752, entitled "Low-Profile Slide Structure" filed herewith.
Hardened steel ball bearings are used frequently in ball bearing retainer assemblies of the type used in telescoping slide assemblies. When a telescoping slide assembly is installed in an application where shock and vibration exists, the hardened steel ball bearings used in the retainer assemblies begin to peen a hemispherical depression into the ball bearing raceways provided in the slide members on either side of the steel ball bearings. In effect, each ball bearing is "embedded" into the adjacent softer metal used in the slide members to define the ball bearing raceways during vibration or shock applied to the telescoping slide assembly. Over a period of time, the operability of such a slide assembly can be impaired by the formation of these hammered or peened hemispherical depressions. Whenever such a slide assembly is "cycled" (i.e., moved back and forth between extended and retracted positions), the steel ball bearings are moved rapidly into and out of these peened hemispherical depressions. This creates unwanted friction and drag and impairs slide assembly operation. The rough action of ball bearings moving into and out of peened hemispherical depressions formed in ball bearing raceways is similar to driving a vehicle along and over the ties in a railroad track.
What is needed is an improved ball bearing retainer assembly that is sturdy enough to support sliding movement of even a heavy-duty slide assembly that is exposed to vibration or shock, yet is not hampered by unwanted friction and drag caused by any peened hemispherical depressions that may be formed by vibration or shock while the slide assembly occupies its fully retracted closed position. Such an improvement would be welcomed by consumers that use telescoping slide assemblies in environments which expose those assemblies to shock and vibration.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.